Today I gave the girls pieces of card-stock to decorate as birthday cards for the neighbor. Mischief also returned to me with her little hand clutching what appeared to be a wad of fabric, I could see an edge peeking out. She told me she also had a present to give our neighbor grandma. I cautiously asked her what, thinking it might be a small rubbery toy that their cat would accidentally eat, but she informed me that it was a rock. We added it to the pile and it brought back a memory of when I was a kid, I used to give rocks as gifts. I have a clear memory of hurriedly searching through our yard for rocks to fill up an empty candy box to give to a sibling for their birthday when they got home from school.
So a rock wrapped in a little fabric scrap, totally acceptable gift in my opinion.